• Biomedical Science Letters
• /
• v.13 no.2
• /
• pp.105-110
• /
• 2007

Aspartyl-tRNA synthetase (AspRS) exists in two different forms with respect to tRNA recognition. The discriminating enzyme (D-AspRS) recognizes only tRNA$^{Asp}$, while the non-discriminating one (ND-AspRS) also recognizes tRNA$^{Asn}$ and therefore forms both Asp-tRNA$^{Asn}$ and Asp-tRNA$^{Asp}$. Plus primary sequence distinguishes two general groups of AspRS. There is a predominantly bacterial-type, larger AspRS (about 580 aa) in addition to a shorter archaeal/eukaryotic type (about 430 aa). In vivo data made clear that discriminating and non-discriminating enzymes exist in both groups. The determinants in the protein sequence responsible for tRNA discrimination are not hewn. The AspRS from Acidithiobacillus ferrooxidans might be suggested ND-AspRS fur missing of AsnRS in genomic sequencing data. Therefore, we analyzed the AspRS from A. ferrooxidans with in vitro aminoacylation assay with E. coli unfractionated tRNA, in vivo missense suppression assay with tipA34 mutant and Northern hybridization with probes which were specific with tRNA$^{Asp}$ or tRNA$^{Asn}$. The AspRS from A. ferrooxidans produced more Asp-tRNA than that from E. coli. Only aspS gene from A. ferrooxidans suppressed trpA34 strain in minimal media without tryptophan. Only AspRS from A. ferrooxidans showed mischarged Asp-tRNA$^{Asn}$ band. Therefore, AspRS from A. ferrooxidans is definitely ND-AspRS.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.8
• /
• pp.1186-1194
• /
• 2009

The objective of this study was to estimate the optimum dietary essential amino acid pattern for male Taiwan country chicks. A series of experiments was conducted with chicks, 14 d of age, for 2 wks. A basal synthetic diet was established using a dose response test for all essential amino acids referring to the broiler requirements recommended by NRC (1994). Twelve chicks were sacrificed at the beginning to provide initial body nitrogen data, and every group of six birds received the basal diet or a diet with a deficiency in a single essential amino acid in twenty one treatments by intubation according to their daily metabolic body weight (MBW). Deposited body nitrogen was determined using comparative slaughtering. According to the daily intake from the limiting amino acid per unit of MBW and the body nitrogen accretion rates for every two deficient groups with the same limiting amino acid but at different levels, a corresponding straight line was computed for each essential amino acid to intersect with a horizontal line made by the body nitrogen accretion rate of the control group. The x coordinate of the intersection represented the daily requirement for growth plus maintenance based on MBW corresponding to the essential amino acid. The amino acid ratios can be considered as the optimum pattern of dietary essential amino acids. The results, expressed with respect to lysine = 100, were arginine 105, methionine 81, histidine 34, tryptophan 18, leucine 103, phenylalanine 135, isoleucine 69, threonine 65 and valine 79. This pattern could be utilized to compute the dietary requirements (g/kg feed) for all essential amino acids by multiplying by the requirement of a single essential amino acid cited from the literature.

• Fisheries and Aquatic Sciences
• /
• v.1 no.2
• /
• pp.201-208
• /
• 1998

A protease, which had no tryptic and chymotryptic activity, was purified from the hepatopancreas of shrimp, P. japonicus, through ammonium sulfate fractionation, Q­Sepharose ionic exchange, benzamidine Sepharose 6B affinity, and Sephacryl S-100 gel chromatography. Molecular weight (M.W.) of the protease was estimated to be 24 kDa by gel filtration and showed a single peptide band by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). The protease had a low ratio of acidic to basic amino acids, which is different with pro teases from marine animals. The enzyme was partially inhibited by benzamidine, tosyl-L-lysine chioromethyl ketone (TLCK), phenylmethylsulfonyl fluoride (PMSF), soybean trypsin inhibitor (SBTI), and pepstatin. The enzyme did not have any activity against benzoyl-D,L-arginine p-nitroanilide (BAPNA) or benzoyl-L-tyrosine ethyl ester (BTEE) which is a specific substrate of trypsin and chymotrypsin, respectively. However, the enzyme showed activity forward N-CBZ-L-tyrosine p-nitrophenyl ester (CBZ-Tyr-pNE), N­CBZ-L-tryptophan p-nitrophenyl ester (CBZ-Trp-pNE), and N-CBZ-L-proline p-nitrophenyl ester (CBZ-Pro-pNE). The protease did not showed tryptic and chymotryptic activity, which was not reported in shrimp hepatopancreas.

• Animal Bioscience
• /
• v.36 no.10
• /
• pp.1584-1595
• /
• 2023

Objective: This study was conducted to evaluate the effect of a low-protein diet on growth performance, carcass traits, nutrient digestibility, blood profiles, and odor emissions in growing-finishing pigs. Methods: A total of 126 crossbred pigs ([Yorkshire×Landrace]×Duroc) with an average body weight (BW) of 38.56±0.53 kg were used for a 14-week feeding trial. Experimental pigs were allotted to one of 6 treatments in 3 replicates of 7 pigs per pen in a randomized complete block design. Pigs were fed each treatment diet with different levels of crude protein (CP). Phase 1 (early growing): 14%, 15%, 16%, 17%, 18%, 19%; phase 2 (late growing): 13%, 14%, 15%, 16%, 17%, 18%; phase 3 (early finishing): 12%, 13%, 14%, 15%, 16%, 17%; phase 4 (late finishing): 11%, 12%, 13%, 14%, 15%, 16%. All experimental diets in each phase were contained the same concentration of lysine (Lys), methionine (Met), threonine (Thr), and tryptophan (Trp). Results: Over the entire experimental period, there was no significant difference in BW, average daily feed intake, and gain-to-feed ratio among all treatments (p>0.05), but a quadratic effect (p = 0.04) was observed in average daily gain (ADG) during the late finishing phase with higher ADG in Group D. Blood urea nitrogen concentration linearly increased with an increase in dietary CP levels (p<0.01). Regarding nutrient digestibility, excreted nitrogen in urine and feces and nitrogen retention linearly increased as the CP level increased (p<0.01). A linear effect was observed with increasing CP levels in amines, ammonia, and hydrogen sulfide in odor emissions (p<0.01). No significant effects were observed in the measurements of carcass traits and meat characteristics (p>0.05). Conclusion: In phase feeding, reducing the CP level to 14% in early-growing pigs, 13% in late-growing pigs, 12% in early-finishing pigs, and 11% in late-finishing pigs is recommended.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.1
• /
• pp.102-110
• /
• 2015

The purpose of this experiment was to determine and compare the digestibility of crude protein (CP) and amino acids (AA) in full-oil (no oil extracted) and de-oiled (oil extracted) corn distillers dried grains with solubles (DDGS) with different condensed distillers solubles (CDS) ratios. Six barrows ($29.6{\pm}2.3kg$) fitted with ileal T-cannula were allotted into a $6{\times}6$ Latin square design. Each period was comprised of a 5-d adaption period followed by a 2-d collection of ileal digesta. The five test diets contained 62% DDGS as the sole source of AA. A nitrogen-free diet was used to measure the basal endogenous losses of CP and AA. Chromic oxide (0.3%) was used as an index in each diet. The results showed that CP and AA were very similar in 5 DDGS, but the standardized ileal digestibility (SID) of lysine (from 56.16% to 71.15%) and tryptophan (from 54.90% to 68.38%) had the lowest values and largest variation within the essential AA, which suggests reduced availability of AA and different levels of Maillard reactions in the five DDGS. The apparent ileal digestibility and SID of CP and most of AA in full-oil DDGS (sources 1 and 2) were greater (p<0.05) than de-oiled DDGS (sources 3, 4, and 5). Comparing the AA SID in the 5 DDGS, full-oil with low CDS ratio DDGS (source 1) had non-significantly higher values (p>0.05) than full-oil with high CDS ratio DDGS (source 2); however, the SID of most AA of de-oiled with low CDS ratios DDGS (source 3) were non-significantly lower (p>0.05) than de-oiled with high CDS ratio DDGS (source 4); and the de-oiled DDGS with middle CDS ratio (source 5) but with different drying processing had the lowest SID AA values. In conclusion, de-oiled DDGS had lower SID of CP and AA than full-oil DDGS; a higher CDS ratio tended to decrease the SID of AA in full-oil DDGS but not in de-oiled DDGS; and compared with CDS ratio, processing, especially drying, may have more of an effect on AA digestibility of DDGS.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.11
• /
• pp.1616-1624
• /
• 2016

The aim of present experiment was to investigate the effect of protein reduction in commercial broiler chicken rations with incorporation of de-oiled rice bran (DORB) and supplementation of limiting amino acids (valine, isoleucine, and/or tryptophan) with ration formulation either on total amino acid (TAA) or standardized ileal digestible amino acids (SIDAA). The experimental design consisted of $T_1$, TAA control; $T_2$ and $T_3$, 0.75% and 1.5% protein reduction by 3% and 6% DORB incorporation, respectively by replacing soybean meal with supplemental limiting amino acids to meet TAA requirement; $T_4$, SIDAA control, $T_5$ and $T_6$, 0.75% and 1.5% protein reduction by DORB incorporation (3% and 6%) with supplemental limiting amino acids on SIDAA basis. A total of 360 dold fast growing broiler chicks (Vencobb-400) were divided into 36 homogenous groups of ten chicks each, and six dietary treatments described were allocated randomly with six replications. During 42 days trial, the feed intake was significantly (p<0.05) reduced by TAA factor compared to SIDAA factor and protein factor significantly (p<0.05) reduced the feed intake at 1.5% reduction compared to normal protein group. This was observed only during pre-starter phase but not thereafter. The cumulative body weight gain (BWG) was significantly (p<0.05) reduced in TAA formulations with protein step-down of 1.5% ($T_3$, 1,993 g) compared to control ($T_1$, 2,067 g), while under SIDAA formulations, BWG was not affected with protein reduction of 1.5% ($T_6$, 2,076 g) compared to $T_4$ (2,129 g). The feed conversion ratio (FCR) was significantly (p<0.05) reduced in both TAA and SIDAA formulations with 1.5% protein step-down ($T_3$, 1.741; $T_6$, 1.704) compared to respective controls ($T_1$, 1.696; $T_4$, 1.663). The SIDAA formulation revealed significantly (p<0.05) higher BWG (2,095 g) and better FCR (1.684) compared to TAA formulation (2,028 g; 1.721). Intake of crude protein and all limiting amino acids (SID basis) was higher in SIDAA group than TAA group with resultant higher nitrogen retention (4.438 vs 4.027 g/bird/d). The nitrogen excretion was minimized with 1.5% protein reduction (1.608 g/bird) compared to normal protein group (1.794 g/bird). The serum uric acid concentration was significantly reduced in $T_3$ (9.45 mg/dL) as compared to $T_4$ (10.75 mg/dL). All carcass parameters were significantly (p<0.05) higher in SIDAA formulation over TAA formulation and 1.5% protein reduction significantly reduced carcass, breast and thigh yields. In conclusion, the dietary protein can be reduced by 0.75% with TAA formulation and 1.5% with SIDAA formulation through DORB incorporation and supplementation of limiting amino acids and among formulations, SIDAA formulation was better than TAA formulation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.6
• /
• pp.817-823
• /
• 2000

Four groups of six growing gilts each were fed ad libitum diets composed of cereals and soyabean (SBM) or rapeseed (RSM) meal and containing two levels of crude protein: high - 18.0% (RSM-H) and 16.9% (SBM-H) or low - 15.6% (RSM-L) and 15.1% (SBM-L). The diets were balanced by supplementation with crystalline amino acids and contained apparent ileal digestible lysine, methionine, threonine and tryptophan in proportions (1.00:0.32:0.57:0.18) according to CVB (1995). Voluntary feed intake, weight gain and slaughter and chemical body composition of animals were assessed. Protein and energy balances from 25 to 70 kg body weight were calculated by the comparative slaughter method. Protein source had a significant effect on voluntary feed intake; it was 0.12 kg/d lower in pigs fed the SBM than RSM-diets. Pigs fed on the SBM-L diet consumed the least amount of feed (2.17 kg). Daily gain (average, $900{\pm}12.59g$) and feed conversion ratio ($2.54{\pm}0.04kg/kg$) were not statistically affected by source (SMB and RSM) and protein level (high and low). In empty body similar amounts (g/kg) of protein (163 g), water (635 g) and ash (28 g) were found. However, pigs fed the RSM-L diet were fatter than those fed the SBM-L diet (188 vs. 161 g/kg). No statistical differences were observed in daily protein deposition, which on average amounted to $142{\pm}11g$, or carcass characteristics. An improvement of crude protein utilization by 6.3 percentage units was found by decreasing the protein concentration in the diets. Heat production in the body was not significantly affected by the treatments.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.6
• /
• pp.928-939
• /
• 2003

A study was carried out to determine the effect of de-hulling on apparent and true ileal amino acids digestibility of soybean meals for growing pigs. Twenty barrows (Duroc${\times}$Large white${\times}$Longer white) were fitted with a simple T-cannula at the distal ilium. Digestibility of 20 experimental diets was determined, nine of them were de-hulled soybean meal diets, and nine of them were regular soybean meal diets and two low protein casein diets for determination of endogenous amino acid correction for true digestibility determination. A TEX>$5<{\times}5<$ Latin Squares Design was adopted in this trail. The results showed that de-hulling increased apparent ileal digestibility of isoleucine, threonine, aspartic, tyrosine and indispensable and dispensable amino acid (p<0.05) in soybean meals. Furthermore, dehulling is also increased apparent digestibility of arginine, leucine, lysine, phenylalanine, alanine, glutamic acid, serine and gross amino acids (p<0.01). However, there were no significant differences found for histidine, methionine, tryptophan, cystine and glycine (p>0.05). Similar responses were found for true ileal digestibility. In three dehulled and non-dehulled pairs soybean meals from the same respective sources, de-hulling increased apparent digestibility of lysine, methionine, threonine and cystine 1.42%, 2.06%, 2.18% and 1.40% respectively. True digestibility of lysine, methionine, threonine and cystine was increased 1.65%, 1.94%, 2.30% and 1.82% respectively. A prediction equation for true ileal amino acid digestibility (including lysine and arginine) was established by multivariate linear regression. The independent variables included relevant amino acid, organic matter, crude protein, ether extract and nitrogen free extract. The coefficient R2 values of lysine and agrinine were 0.596 and 0.531 respectively. According to the crude protein content, a prediction equation for lysine and arginine content in soybean meal was also established by single linear regression. The coefficient $R^2$ values of lysine and agrinine were 0.636 and 0.636 respectively.

• Animal Bioscience
• /
• v.37 no.8
• /
• pp.1474-1482
• /
• 2024

Objective: The experiment aimed to determine the standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in 10 brown rice samples fed to pigs, and to construct predictive models for SID of CP and AA based on the physical characteristics and chemical composition of brown rice. Methods: Twenty-two cannulated pigs (initial body weight: 42.0±1.2 kg) were assigned to a replicated 11×3 incomplete Latin square design, including an N-free diet and 10 brown rice diets. Each period included 5 d adaptation and 2 d ileal digesta collection. Chromic oxide was added at 0.3% to all the diets as an indigestible marker for calculating the ileal CP and AA digestibility. Results: The coefficients of variation of all detected indices for physical characteristics and chemical composition, except for bulk weight, dry matter (DM) and gross energy, in 10 brown rice samples were greater than 10%. The SID of CP, lysine (Lys), methionine, threonine (Thr), and tryptophan (Trp) in brown rice was 77.2% (62.6% to 85.5%), 87.5% (80.3% to 94.3%), 89.2% (78.9% to 98.9%), 55.4% (46.1% to 67.6%) and 92.5% (86.3% to 96.3%), respectively. The best prediction equations for the SID of CP, Lys, Thr, and Trp were as following, SID_CP = -664.181+8.484×DM (R² = 0.40), SID_Lys = 53.126+6.031×ether extract (EE)+0.893×thousand-kernel volume (R² = 0.66), SID_Thr = 39.916+7.843×EE (R² = 0.41), and SID_Trp = -361.588+4.891×DM+0.387×total starch (R² = 0.85). Conclusion: Overall, a great variation exists among 10 sources of brown rice, and the thousand-grain volume, DM, EE, and total starch can be used as the key predictors for SID of CP and AA.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.5
• /
• pp.655-667
• /
• 2001

This experiment was conducted to investigate the effect of feeding a low CP diet supplemented with synthetic amino acids on performance, nutrient utilization and carcass characteristics of finishing pigs fed under a three-phase feeding regimen. Ninety-six finishing pigs (Landrace$\times$Large White$\times$Duroc), $55.75kg{\pm}0.65$ of initial body weight, were blocked by weight and sex and allotted to four dietary treatments in a randomized block design. There were six pens per treatment and four pigs per pen. Pigs were fed a 16%-14%-12% CP (for phase I-II-III, respectively), sequence of diets. Dietary treatments were 1) Control, 2) Con+L (a sequence of diets reduced in CP by l percentage unit with lysine (L) supplementation, 3) Con+LMT (a sequence of diets reduced in CP by 2 percentage unit with LYS, methionine (MET) and threonine (THE) supplementation) and 4) Con+LMTT (a sequence of diets reduced in CP by 3 percentage unit with LYS, MET, THR and tryptophan (TRP) supplementation). The finishing period (55 to 105 kg) was divided into three phases (55 to 72 kg, 72 to 90 kg and 90 to 105 kg). Pigs fed either the control or Con+L diet grew faster (p<0.05) than pigs fed the Con-LMT or Con+LMTT diet. There was no difference in ADFI among dietary treatments. Phosphorus (P) digestibility was lowest in the control group and highest in the Con+LMTT group (p<0.05). Within each phase, no significant differences in dry matter (DM) and CP digestibilities were found. Although some amino acid digestibilities were affected by dietary treatments, digestibilities of essential amino acids (EAA), non-essential amino acids (NEAA) and total amino acid were not significantly influenced by dietary treatments. For the entire experiment periods, Con+L, Con+LMT and Con+LMTT treatments resulted in 13.4, 18.8 and 21.6% lower total N excretion compared with the control. Con+LMT and Con+LMTT treatments showed significantly lower BUN concentration compared with the control and Con+L treatment (p<0.05), but there was no significant difference in BUN concentration between pigs fed the control and Con+L treatment or between pigs fed Con+LMT and Con+LMTT treatments (p>0.05). Carcass length, backfat thickness and carcass grade were not significantly affected by dietary treatments (p>0.05). In conclusion, reducing dietary CP level by 1 percentage unit and supplementing only LYS at each phase could be a very beneficial feeding strategy for finishing pigs fed under a three phase feeding regimen in terms of both environmental and economical aspects.